3ds Max 2012 Bible - Kelly L. Murdock [440]
Note
Be sure to use the Variation values liberally to get more realistic particle behavior. •
In the Particle Timing group, you can set when the emitting process starts and stops. Using the Display Until value, you also can cause the particles to continue displaying after the emitting has stopped. The Life value is how long particles stay around, which can vary based on another Variation setting.
When an emitter is animated (such as moving back and forth), the particles can clump together where the system changes direction. This clumping effect is called puffing. The Subframe Sampling options help reduce this effect. The three options are Creation Time (which controls emitting particles over time), Emitter Translation (which controls emitting particles as the emitter is moved), and Emitter Rotation (which controls emitting particles as the emitter is rotated). All three options can be enabled, but each one that is enabled adds the computation time required to the render.
Note
The Subframe Sampling options increase the rendering time and should be used only if necessary. •
You can specify the particle size along with a Variation value. You also can cause the particles to grow and fade for a certain number of frames.
The Seed value helps determine the randomness of the particles. Clicking the New button automatically generates a new Seed value.
Note
If you clone a particle system and each system has the same Seed value, then the two systems will be exactly the same. Two cloned particle systems with different Seed values will be unique. •
Particle Type rollout
The Particle Type rollout, shown in Figure 41.6, lets you define the look of the particles. At the top of the rollout are three Particle Type options: Standard Particles, MetaParticles, and Instanced Geometry.
FIGURE 41.6
The Particle Type rollout (shown in four parts) lets you define how the particles look.
If you select Standard Particles as the particle type, you can select which geometric shape you want to use from the Standard Particles section. The options are Triangle, Special, Constant, SixPoint, Cube, Facing, Tetra, and Sphere.
The Special type consists of three intersecting planes, which are useful if you apply maps to them. The Facing type is also useful with maps; it creates a simple square face that always faces the viewer. The Constant type maintains the same pixel size, regardless of the distance from the camera or viewer. The Six Point option renders each particle as a 2D six-pointed star. All other types are common geometric objects.
Tutorial: Creating a fireworks fountain
For an example of the Super Spray particle system, you create a fireworks fountain. Fireworks are essentially just lots of particles with a short life span and a high amount of self-illumination. (Tell yourself that the next time you watch a fireworks display.)
Cross-Reference
The ready-made material for this example uses the Glow Render effect to make the particles glow. You can learn more about render effects in Chapter 46, “Using Atmospheric and Render Effects.” •
To create a fireworks fountain using a particle system, follow these steps:
1. Open the Fireworks fountain.max file from the Chap 41 directory on the CD.
This file includes a simple fountain base and the Gravity space warp to cause the particles to curve back toward the ground.
Tip
Some of the most amazing special effects are made possible by combining particle systems with Space Warps. •
2. Select the Create⇒Particles⇒Super Spray menu command, drag in the Top view, and position the system at the top of the cylinder with the direction arrow pointing toward the sky.
3. Open the Modify panel, and set the Off Axis Spread to 45 and the Off Plane Spread to 90. In the Particle Generation rollout, set the Total of particles to 2000 with a Speed of 20 and a Variation of 100. Set the Emit Start to 0 and the Emit Stop